package main
// 存在未知error

import (
	"fmt"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"time"
)

func main()  {
	start :=time.Now()
	ch := make(chan string)
	for _,url:=range os.Args[1:]{
		go fetch(url,ch)
	}
	for range os.Args[1:]{
		fmt.Println(<-ch)
	}
	fmt.Printf("%.2fs elapsed\n",time.Since(start).Seconds())
}

func fetch(url string,ch chan<- string){
	start := time.Now()
	resp,err:=http.Get(url)
	if err!=nil{
		ch <- fmt.Sprint(err)
		return
	}
	nbytes,err := io.Copy(ioutil.Discard,resp.Body)
	resp.Body.Close()
	if err!=nil{
		ch <- fmt.Sprint("while reading %s: %v",url,err)
		return
	}
	secs :=time.Since(start).Seconds()
	ch <- fmt.Sprintf("%.2fs %7d %s",secs,nbytes,url)
}
